1. Technical Field of the Invention
The invention concerns a magnetic sensor that is used to detect the rotation of an operating component of a machine. More particularly, the invention concerns the use of magnets and an associated magnetosensitive device such as a hall-effect sensor which detects the operational rotation of a throttle, for example as is used to control the engine of a motorcycle or automobile.
2. Description of Related Art
It is known that two opposing magnets may be affixed to a cylinder so that the magnets rotate in opposed orientation as the cylinder rotates on its axis. It is also known that the moving magnetic field of the magnets can be detected by a stationary magnetosensitive detector such as a hall-effect sensor that is disposed within the rotating cylinder and between the opposed magnets. The sensor detects the changing angle of magnetic flux at its upper flux sensitive face as the magnets rotate, and generates a signal which corresponds to the degree of rotation of the cylinder. A known device of this type positioned a flux detector on the geometric and magnetic axis of symmetry of the opposing magnets and detected a sinusoidal change in magnetic flux as the magnets were rotated. This device had an acceptable error for rotation only over a relatively small angular distance of about ±30°.
It would be advantageous to be able to utilize opposing magnets and an associated hall-effect sensor or other magnetosensitive device to detect a linear change in magnetic flux with improved accuracy over a substantially increased range of angular movement. It would also be advantageous to select parameters for the components of such a device in order to optimize the accuracy and linearity of flux detection over a desired increased range of angular movement. An improved angular position sensor of this type would be well suited, for example, to detect the angular movement of the throttle control of a motorcycle or automobile. This improved sensor could also be used to accurately detect the rotation of components for any device.